From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E18C11A2C1E; Fri, 17 May 2024 20:45:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715978738; cv=none; b=LmWvKXIdBEqvUgOnlx1xAIfpi2M+xEvbNWmMTCRw1/BvUEMfv/X5fMBPjXa7ICa/QnpnPKUzLqF+Q3bvuDzLErutUHqdenIrFkFCyaEvZBvBbwHC2+6e3hFxK+fdPK4WNSwDfRy6x1j8kvqtJ2fuH+cUrf1VVYjAoPXlJTHbiiU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715978738; c=relaxed/simple; bh=gBMpZMWfyzUQArH1dlBEIH4whj5xwu3YOj/Tb2+i0G0=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=YSS33C2mgnnx8tj+NGG+pQ2Ox5XkhtwLdoijrDhLuEl7XGXmOM6pu37mLfJs/6cTBSQg2IrmfPu3IIR3dozsXEltJvUhNBNWq2eloQ6Zm95vsjG010vs9k7EsMHdfVaNCp+HifWGTVK1NadZ4bHhZJ/2P7EpjNlyEQkzvvn0Ezs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=L3cGhsKG; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="L3cGhsKG" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E1178C2BD10; Fri, 17 May 2024 20:45:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1715978737; bh=gBMpZMWfyzUQArH1dlBEIH4whj5xwu3YOj/Tb2+i0G0=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=L3cGhsKGUMzJO6W4/EstavUeJELZ5ekwnE7cgs1Yn7PdX+my8Oyj9ZLXUxvw0rW50 1quIhMJ8qENat703FZDUnlX4WdP4FDoKFbMhwz7djdERi+DgbyeXXZ7ApcNYIS1xca 7xz7+ZZPyKdAPdX/OvnIjA4n15h7+lDF4xkR5Da8xVeThbwn5oRSSdZguL1DpCq1Ct r89ZNHTb2Yu9lo8JtG+4erZSNzmbHiNCHk5wOZFudIhRvVT2E3Q+h33uPvq7qsU4vT nf4fZGBvQJfa/kNO3F1XGWRhlRRJudfKeqXTpvVrBdQXeDdcWZFPQ65mC9/YTphQ+B 5od8+ab9nvTCQ== Date: Fri, 17 May 2024 21:45:32 +0100 From: Simon Horman To: Kenton Groombridge Cc: johannes@sipsolutions.net, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, linux-wireless@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org, Kees Cook Subject: Re: [PATCH v2] wifi: mac80211: Avoid address calculations via out of bounds array indexing Message-ID: <20240517204532.GC475595@kernel.org> References: <20240517145420.8891-1-concord@gentoo.org> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240517145420.8891-1-concord@gentoo.org> On Fri, May 17, 2024 at 10:54:20AM -0400, Kenton Groombridge wrote: > req->n_channels must be set before req->channels[] can be used. > > This patch fixes one of the issues encountered in [1]. > > [ 83.964252] ------------[ cut here ]------------ > [ 83.964255] UBSAN: array-index-out-of-bounds in net/mac80211/scan.c:364:4 > [ 83.964258] index 0 is out of range for type 'struct ieee80211_channel *[]' > [ 83.964260] CPU: 0 PID: 1695 Comm: iwd Tainted: G O T 6.8.9-gentoo-hardened1 #1 > [ 83.964262] Hardware name: System76 Pangolin/Pangolin, BIOS ARB928_V00.01_T0025ASY1_ms 04/20/2023 > [ 83.964264] Call Trace: > [ 83.964267] > [ 83.964269] dump_stack_lvl+0x3f/0xc0 > [ 83.964274] __ubsan_handle_out_of_bounds+0xec/0x110 > [ 83.964278] ieee80211_prep_hw_scan+0x2db/0x4b0 > [ 83.964281] __ieee80211_start_scan+0x601/0x990 > [ 83.964284] ? srso_alias_return_thunk+0x5/0xfbef5 > [ 83.964287] ? cfg80211_scan+0x149/0x250 > [ 83.964291] nl80211_trigger_scan+0x874/0x980 > [ 83.964295] genl_family_rcv_msg_doit+0xe8/0x160 > [ 83.964298] genl_rcv_msg+0x240/0x270 > [ 83.964301] ? __cfi_nl80211_trigger_scan+0x10/0x10 > [ 83.964302] ? __cfi_nl80211_post_doit+0x10/0x10 > [ 83.964304] ? __cfi_nl80211_pre_doit+0x10/0x10 > [ 83.964307] ? __cfi_genl_rcv_msg+0x10/0x10 > [ 83.964309] netlink_rcv_skb+0x102/0x130 > [ 83.964312] genl_rcv+0x23/0x40 > [ 83.964314] netlink_unicast+0x23b/0x340 > [ 83.964316] netlink_sendmsg+0x3a9/0x450 > [ 83.964319] __sys_sendto+0x3ae/0x3c0 > [ 83.964324] __x64_sys_sendto+0x21/0x40 > [ 83.964326] do_syscall_64+0x90/0x150 > [ 83.964329] ? srso_alias_return_thunk+0x5/0xfbef5 > [ 83.964331] ? syscall_exit_work+0xc2/0xf0 > [ 83.964333] ? srso_alias_return_thunk+0x5/0xfbef5 > [ 83.964335] ? syscall_exit_to_user_mode+0x74/0xa0 > [ 83.964337] ? srso_alias_return_thunk+0x5/0xfbef5 > [ 83.964339] ? do_syscall_64+0x9c/0x150 > [ 83.964340] ? srso_alias_return_thunk+0x5/0xfbef5 > [ 83.964342] ? syscall_exit_to_user_mode+0x74/0xa0 > [ 83.964344] ? srso_alias_return_thunk+0x5/0xfbef5 > [ 83.964346] ? do_syscall_64+0x9c/0x150 > [ 83.964347] ? srso_alias_return_thunk+0x5/0xfbef5 > [ 83.964349] ? do_syscall_64+0x9c/0x150 > [ 83.964351] ? srso_alias_return_thunk+0x5/0xfbef5 u> [ 83.964353] ? syscall_exit_work+0xc2/0xf0 > [ 83.964354] ? srso_alias_return_thunk+0x5/0xfbef5 > [ 83.964356] ? syscall_exit_to_user_mode+0x74/0xa0 > [ 83.964358] ? srso_alias_return_thunk+0x5/0xfbef5 > [ 83.964359] ? do_syscall_64+0x9c/0x150 > [ 83.964361] ? srso_alias_return_thunk+0x5/0xfbef5 > [ 83.964362] ? do_user_addr_fault+0x488/0x620 > [ 83.964366] ? srso_alias_return_thunk+0x5/0xfbef5 > [ 83.964367] ? srso_alias_return_thunk+0x5/0xfbef5 > [ 83.964369] entry_SYSCALL_64_after_hwframe+0x55/0x5d > [ 83.964372] RIP: 0033:0x6200808578d7 > [ 83.964374] Code: 00 00 90 f3 0f 1e fa 41 56 55 41 89 ce 48 83 ec 28 80 3d 7b f7 0d 00 00 74 29 45 31 c9 45 31 c0 41 89 ca b8 2c 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 71 48 83 c4 28 5d 41 5e c3 66 0f 1f 84 00 00 > [ 83.964375] RSP: 002b:0000730c4e821530 EFLAGS: 00000246 ORIG_RAX: 000000000000002c > [ 83.964378] RAX: ffffffffffffffda RBX: 000006dbc456c570 RCX: 00006200808578d7 > [ 83.964379] RDX: 000000000000005c RSI: 000006dbc45884f0 RDI: 0000000000000004 > [ 83.964381] RBP: 0000000000000004 R08: 0000000000000000 R09: 0000000000000000 > [ 83.964382] R10: 0000000000000000 R11: 0000000000000246 R12: 000006dbc456c480 > [ 83.964383] R13: 000006dbc456c450 R14: 0000000000000000 R15: 000006dbc456c610 > [ 83.964386] > [ 83.964386] ---[ end trace ]--- > > [1] https://bugzilla.kernel.org/show_bug.cgi?id=218810 > > v1->v2: > - Drop changes in cfg80211 as requested by Johannes > > Co-authored-by: Kees Cook > Signed-off-by: Kenton Groombridge Thanks Kenton, FWWIW, it seems unfortunate to me that the __counted_by field (n_channels) is set some distance away from the allocation of the flex-array (channels) whose bounds it checks. It seems it would be pretty easy for a bug in the code being updated here to result in an overrun. But in any case, I think this is an improvement and seems correct to me. Reviewed-by: Simon Horman